Device for plugging the interior of a pipe

Abstract: An apparatus for plugging the interior of a pipe (10) that is penetrated by an axis opening (12) including an upright tubular plugger housing (20) attachable at its lower end to have communication with the interior of the pipe (10) through the opening (12). An elongated vertical cylindrical control bar (28) is provided with a plugger (30) at its lower end, the plugger (30) being positioned through the opening (12) into the interior of the pipe (10) to close against further flow of fluid through the pipe (10). A jack (26) is affixed to the plugger housing (20) upper end and telescopically receives the control bar (28), the jack (26) being pivotally affixed to the housing (20) so that the control bar (28), having a plugger (30) on the lower end thereof, can be pivoted relative to the housing (20) and thereby relative to the pipe (10) for proper positioning of the plugger (30) in the pipe (10). The jack (26) serving to axially downwardly or upwardly advance the control bar (28) so that a plugger (30) can be installed or removed from a pipe (10), the jack (26) providing force to expand a sealing cup on the plugging head to seal the inside of the pipe (10). A control bar clamp (38) and latch (126) are used for locking the plugger head (30) in the plugging position.

Description: This invention relates to a device for plugging the interior of a pipe having an internal cylindrical surface. The pipe is provided with an access opening with a diameter which may be substantially equal to or smaller than the diameter of the pipe internal cylindrical surface. Devices exist for forming an opening in the wall of a pipeline even while the pipeline is under liquid or gas pressure. For references to devices that can be used for tapping a pipeline while under pressure, see the following United States Patents: 3,614,252 entitled "Tapping Apparatus"; 4,579,484 entitled "Underwater Tapping Machine"; and 4,880,028 entitled "Completion Machine". In order to terminate the flow through a portion of a pipeline that is under liquid or gas pressure after it has been tapped by a tapping machine as referred to in the above-referenced patents, it is frequently necessary to plug the interior of the pipeline. Normally, in laying out a piping system, valves are installed in the pipeline where it will be necessary to stop or regulate the flow of liquids or gases through the pipeline, but in many instances, it becomes necessary to terminate flow in a portion of a length of a pipeline that does not have a valve previously installed for that purpose. The present invention is directed to a device for performing this service. Others have previously suggested plugging devices for plugging the interior of a pipeline through an opening formed in the wall of the pipeline. For background reference to pipe pluggers, see the following United States Patents 3,665,966 entitled "Pipe Plugger" issued May 30, 1972 and 3,626,475 entitled "High Temperature Pipe-Plugging Apparatus" issued December 7,1971. Great Britain Patent No. 1,340,431 entitled "Pipe Line Plugger" describes and illustrates a type of pipeline plugging system having a plug member coupled to a carrier with a pin in the plug member extending through a slot in the carrier so that on movement of the carrier towards a pipe to be closed the pin will slide in the slot and the plug member will move into a sealing position in the pipe. United States Patent No. 4,202,377 entitled "Pipe Cleaning and Plugging Apparatus" discloses a plugging device in which a plug assembly is attached to the lower end of a shaft assembly, the plug assembly including an annular seal having a circumferential lip portion arranged for sealing engagement with the inside surface of a pipe upon radial outward deflection thereof, the radial outward deflection being achieved by a gear thread arrangement with a rotatable portion of the shaft extending externally of the pipe to be plugged. The external portion is rotatable to thereby rotate through a gearing relationship a threaded feature to draw the annular seal towards a backup plate to radially outwardly expand the annular seal. The British patent does not have provision for radially expanding an annular seal and the United States patent expands a radial seal only by a complex gear arrangement including a rotatable shaft extending outwardly from the pipe being plugged, which cumbersome feature is made unnecessary by the present invention. The present disclosure relates to improvements in a pipe plugging device. The improvements to be described are particularly important in plugging the interior of a pipe that is under substantial liquid or gas pressure. BRIEF SUMMARY OF THE INVENTION This invention relates to a device for plugging the interior of a pipe having an internal cylindrical surface. The pipe is provided with an access opening with a diameter which may be substantially equal to or smaller than the diameter of the pipe internal cylindrical surface. The plugging device includes an upright tubular plugger housing having a flange or other means at the lower end for attachment to a saddle fitting or other device that is in communication with an opening in the pipeline. In the typical operation where a hole has been tapped in an existing pipe that is subject to liquid or gas pressure, a sandwich-type valve is secured to a flange that encompasses the opening in the pipe. According to the present invention there is provided a device for plugging the interior of a pipe having an internal cylindrical surface, the pipe being penetrated by an access opening of a diameter substantially equal to the diameter of the pipe internal cylindrical surface, the plugging device having a vertically oriented plugger body and a backing plate, the plugger body and the backing plate forming mating parts, the plugger body having spaced apart fork portions with a space therebetween, the plugger body having a longitudinal axis, the device being characterized by: the fork portions each having a pair of aligned slots therein, the slots extending in parallel planes that are at an acute angle relative to a plane of the body longitudinal axis and the backing plate having an integral portion having opposed parallel side surfaces, the integral portion being slidably positioned within the space between the fork portions; a pair of spaced-apart axles extending from each of the side surfaces, the axles being received in slots so that the backing plate is retained by the plugger body in a manner to permit vertical and lateral motion of the backing plate relative to the plugger body as the axles move in the slots, the backing plate having a forward surface with a frusto-conical circumferential edge; an elastomeric cup supported in variably spaced sliding relationship to the backing plate, the cup having a circumferential outer sealing surface of diameter slightly greater than the internal diameter of the pipe to be plugged, the cup having a rearward surface facing the backing plate forward surface, the cup rearward surface being partially defined by an internal circumferential frusto-conical surface that mates with the backing plate frusto-conical edge; a stub downwardly extending from the backing plate and positioned rearwardly of the cup providing means to engage the interior surface of a pipe to be plugged to cause the backing plate to be slidably displaced forwardly of the plugger body as the plugger body is forced downwardly into a pipe to be plugged, the backing plate frusto-conical circumferential edge engaging the cup internal circumferential frusto-conical surface by the forward displacement of the backing plate whereby the cup is outwardly expanded as the backing plate is forced against the cup rearward surface to provide improved sealing relationship between the cup sealing surface and a pipe internal cylindrical surface; and means to secure the plugger body to the lower end of an elongated control bar by which the device is inserted into a pipe to be plugged. Preferably, said backing plate has a central opening therethrough between and paralleled to said paralleled side surfaces, and including: a cylindrical bolt slidably displaceably received in said backing plate opening, said cup being secured to a forward end of the bolt to provide said variably spaced sliding relationship of said cup relative to said backing plate. Preferably said device includes a rigid nose plate secured to said shaft forward end, said elastomeric cup having a forward surface in contact with said nose plate. Further preferably in such arrangement said backing plate has a guide opening therein displaced from and paralleled to said first mentioned central opening and including: a guide pin supported by and extending from said nose plate, the guide pin being slidably received in said backing plate guide opening whereby the axial orientation of said nose plate and said elastomeric cup relative to said backing plate is retained as said nose plate and elastomeric cup are displaced relative to said backing plate. DESCRIPTION OF THE DRAWINGS Figure 1 is an elevational view of a pipeline to which is attached a flange that communicates with an access opening in a pipe. Supported on the flange is a sandwich-type valve that is used to open and close communication with the access opening. Positioned on top of the sandwich valve is a plugger housing and on the plugger housing is a jack. A control bar is telescopically received by the plugger housing and jack and is used in installing a plugger head into the pipe through the access opening. The plugger head can then be positioned to plug the pipeline against flow of liquid or gas therethrough. Figure 2 is an exploded view of the plugger head, according to the invention. Figure 3 is an elevational rear view of the plugger head taken along the line of 25-25 of Figure 2. Figure 4 is a cross-sectional elevational view of the plugger head as taken along the line 26-26 of Figure 3 illustrating the apparatus by which the closure cup can be axially advanced into seating engagement with the interior of a pipe. DETAILED DESCRIPTION Referring to the drawings and first to Figure 1, a pipe indicated by the numeral 10 has an opening 12 in the sidewall thereof. Opening 12 can be formed such as by a tapping operation as revealed in U.S. Patents 3,614,252; 4,579,484 and 4,880,028, that is, opening 12 can be formed in pipe 10 even while the pipe is under liquid or gas pressure. In conjunction with the formation of an opening in a pipe that is under pressure, a saddle fitting or some other form of fitting 14 is first welded to the exterior of the pipe, the fitting having a flange 16, or external threads to receive a threaded valve. Secured to flange 16 is a sandwich valve 18 which can be opened and closed to provide full diameter access to opening 12, and thus, to the opening of pipe 10. When the sandwich valve is closed, devices can be attached to the top of it, and when opened, access from the devices into the interior of the pipe is provided. The saddle fitting 14 and sandwich valve 18 are not part of the invention but are illustrative of the apparatus with which the invention is employed. This invention relates to apparatus that is secured to the top of sandwich valve 18 as a means of plugging the interior of the pipe. It is to be understood that the apparatus of this invention is not entirely dependent of the use of a sandwich valve - other types in entry devices may be employed but a sandwich valve is typical of the installations to which this invention may be applied. A tubular plugger housing 20 is provided with the flange 22 at the lower end that can be attached directly to sandwich valve 18, or with external threads that may be used with smaller, threaded valves. The lower end configuration of the tubular plugger housing 20 depends on the device to which it is attached -- thus, flange 22 is an illustration of one means of attaching it to apparatus secured to pipe 10. Pivotally secured to the upper end of tubular plugger housing 20 is a pivoted housing closure member 24. Secured to the top of housing closure member 24 is jack 26. Telescopically received within the housing closure member 24 and jack 26 is a cylindrical control bar 28. At the lower end of control bar 28 is a plugging device shown in dotted outline and indicated by the numeral 30. As will be described subsequently, the plugging device 30 according to the invention is employed to sealably close the interior of pipe 10 against the flow of liquid or gas therethrough. The upper end of control bar 28 has an upper handle connector 32 and a lower handle connector 34 which are used to manipulate control bar 28 and thereby plugger 30. Jack 26 is used to move control bar 28 up and down, that is vertically or at least in a vertical plane, with respect to plugger housing 20, the jacking operations being achieved by the manual manipulation of jack handle 36. Attached to the upper end of jack 26 is a bar clamp 38 controlled by lever 40. Bar clamp 38 can be used to lock the control bar in elevational positions with respect to the housing closure member 24. A control bar drag adjust operated by lever 42 is used to control the resistance against downward movement of the control bar 28. All of these components will now be described in greater detail. Figures 2, 3 and 4 show the plugger head according to the invention. As illustrated in Figure 2, this type of plugger head can utilize a control bar 28 that is unitary, that is it does not have a separate internal bar. Control bar 28 is cylindrical and must be actuated by means of the jack in order to provide sufficient force to activate the plugger backing plate 192. Secured to the lower end of control bar 28 is a plugger body 182 having an upper tubular portion 183 that telescopically receives the lower end of control bar 28 so that it can be bolted to the control bar. As best seen in Figure 3, plugger body 182 has two integral spaced apart paralleled fork portions 184 and 186. Each of the fork portions has an elongated upper slot 188 and lower slot 190. The plane of upper slots 188 is paralleled to the plane of lower slots 190 and these planes are at an acute angle relative to the longitudinal axis of the tubular portion 183 which, in turn, means that slots 188 and 190 are at an acute angle with respect to the longitudinal axis of control bar 28. Slidably received between fork portions 184 and 186 is a plugger backing plate 192. Plugger backing plate 192 has opposed parallel sides that slidably engage the spaced apart plugger body fork portions 184 and 186 so that backing plate 192 is securely held between the fork portions. An upper threaded opening 194 is provided in backing plate 192 and, in like manner, a lower threaded opening 198 is provided. These openings receive opposed bolts 198, each bolt supporting a roller 200. Thus, backing plate 192 is positioned between the fork portions of plunger body at the end of the control bar but the backing plate can move laterally of the fork portions as it is traversed upwardly or downwardly according to the lateral direction. A central opening 202 receives a bolt 204 that is threaded and has a nut 206 on the forward end. Received on bolt 204 is nose plate 208 that holds in place an elastomeric cup 210. The backing plate 192 has an integral flange portion 212 that supports elastomeric cup 210. The flange portion 212 of backing plate 192 has a sloped circumferential surface 214 that engages the rearward conical shaped portion of cup 210. This sloped surface engages the conical internal surface of cup 210 and as it is forced outwardly it tends to expand elastomeric cup 210 to thereby more securely fit against the interior cylindrical wall of a pipe. The rearward end of bolt 204 receives bar 216 welded to it to limit the forward motion of the bolt, as it engages the rear edges of fork portions 184 and 186. Secured to lower end of backing plate 192 is a foot portion 218, which may, as illustrated, be integrally formed with the backing plate. The function of foot portion 218 is to engage the internal lower surface of a pipe in which the plugger is forced. As downward pressure is applied by jack 26 on control bar 28 and thereby onto backing plate 192, foot portion 218 engages the interior of the pipe and pushes backing plate upwardly causing it to move forwardly with respect to slots 188 and 190 and thereby force the backing plate 192 into cup 210 which is held in place by nose plate 208 via bolt 204 and nut 206, thus expanding cup 210 and forcing it out radially into the interior of a pipe. Jack 26 which applies the force necessary to accomplish this expansion is secured by setting clamp 38 and latch 126. Foot portion 218 may be provided with a wheel (not shown) to roll on the interior surface of a pipe as the plugger is positioned in a pipe. A pin 220 is secured to nose plate 208 and extends through elastomeric cup 210 and opening 222 in backing plate 192. Pin 220 serves to guide and position the nose plate and elastomeric cup 210 as it is moved with respect to backing plate 192. Pin 220 thus guides the nose plate and cups as these members move with respect to each other. The plugging device as described herein is primarily for use to temporarily close off a pipe. After its need is no longer required, the plugger head is pulled out of the pipe, but the opening through which the plugger head is installed must be sealed. For this purpose, the usual procedure is to thread or use a locking-type plug (not shown) in the top of saddle fitting 14 to thereby enable valve 18 to be removed. After valve 18 is removed, a blind flange may be affixed to saddle fitting flange 16 to complete the operation. Completion plug holder 254 having actuating members 256 and 258 are illustrated for the purpose of showing that the device for plugging the interior of a pipe as been described herein can be used for this and other purposes.

Claims: A device for plugging the interior of a pipe having an internal cylindrical surface, the pipe being penetrated by an access opening of a diameter substantially equal to the diameter of the pipe internal cylindrical surface, the plugging device having a vertically oriented plugger body (182) and a backing plate (192), the plugger body and the backing plate forming mating parts, the plugger body (182) having spaced apart fork portions (184, 186) with a space therebetween, the plugger body (182) having a longitudinal axis, the device being characterized by: the fork portions (184, 186) each having a pair of aligned slots (188, 190) therein, the slots extending in parallel planes that are at an acute angle relative to a plane of the body longitudinal axis and the backing plate (192) having an integral portion having opposed parallel side surfaces, the integral portion being slidably positioned within the space between the fork portions (184, 186); a pair of spaced-apart axles (198) extending from each of the side surfaces, the axles being received in slots (188, 190) so that the backing plate (192) is retained by the plugger body (182) in a manner to permit vertical and lateral motion of the backing plate (192) relative to the plugger body as the axles (198) move in the slots (188, 190), the backing plate (192) having a forward surface with a frusto-conical circumferential edge (214); an elastomeric cup (210) supported in variably spaced sliding relationship to the backing plate (192), the cup having a circumferential outer sealing surface of diameter slightly greater than the internal diameter of the pipe to be plugged, the cup having a rearward surface (211) facing the backing plate forward surface (214), the cup rearward surface (211) being partially defined by an internal circumferential frusto-conical surface that mates with the backing plate frusto-conical edge (214); a stub (218) downwardly extending from the backing plate (192) and positioned rearwardly of the cup (210) providing means to engage the interior surface of a pipe to be plugged to cause the backing plate (192) to be slidably displaced forwardly of the plugger body (182) as the plugger body is forced downwardly into a pipe to be plugged, the backing plate frusto-conical circumferential edge (214) engaging the cup internal circumferential frusto-conical surface (211) by the forward displacement of the backing plate whereby the cup (210) is outwardly expanded as the backing plate is forced against the cup rearward surface to provide improved sealing relationship between the cup sealing surface and a pipe internal cylindrical surface; and means (183) to secure the plugger body (182) to the lower end of an elongated control bar (218) by which the device is inserted into a pipe to be plugged. A plugging device according to claim 1, wherein the backing plate (192) has a central opening (202) therethrough between and paralleled to the paralleled side surfaces, and including: a cylindrical bolt (204) slidably received in the backing plate opening (202), the cup (210) being secured to a forward end of the bolt (204) to provide the variably spaced sliding relationship of the cup (210) relative to the backing plate (192). A plugging device according to claim 2 including: a rigid nose plate (208) secured to the bolt (204) forward end, the elastomeric cup (310) having a forward surface in contact with the nose plate. A plugging device according to claim 3, wherein the backing plate (192) has a guide opening (222) therein displaced from and paralleled to the first mentioned central opening and including: a guide pin (220) supported by and extending from the nose plate (208), the guide pin being slidably received in the backing plate guide opening whereby axial orientation of the nose plate (208) and the elastomeric cup (210) relative to the backing plate (192) is retained as the nose plate (208) and the elastomeric cup (210) are displaced relative to the backing plate (192).

Inventors: ANDREW BILL D, BLEVINS DAVID L, FREEMAN ERIC N, OSBURN COY D, RALLS GENE R, WILSON BUDDY A, ANDREW, BILL D., BLEVINS, DAVID L., FREEMAN, ERIC N., OSBURN, COY D., RALLS, GENE R., WILSON, BUDDY A.
Applicants: TDW DELAWARE INC, TDW DELAWARE, INC.
Application year: 1994
Main classification: F16L55
IPC codes: F16L55, F16L41